The present invention relates a method for producing a protective coating. In addition, the invention relates to a protective coating, a component having a protective coating and use of the protective coating.
In operation of components, in particular components of gas turbines at high temperatures, the free surfaces thereof are exposed to highly corrosive, erosive and oxidizing conditions. For use in gas turbines, such components may be made of a super alloy based on nickel or cobalt, for example. To protect against erosion or corrosion and oxidation, the components are provided with coatings. Coatings for preventing corrosion, oxidation and erosion are disclosed in German Patent Document DE 198 07 636 C1 and German Patent Document DE 199 09 675 A1.
Against this background, the present invention is based on the problem of creating a novel method for producing a protective coating and a novel protective coating. In addition, it is within the scope of the present invention to propose a component having a protective layer and a use of such a protective layer.
According to this invention, at least one lacquer material is provided, whereby the lacquer material is a phosphate or silicate, preferably mixed with particles. At least one layer of the lacquer material or of each lacquer material is applied to a component that is to be protected from erosion. The applied lacquer layer or each applied lacquer layer is converted to a glass layer.
According to an advantageous refinement of the present invention, multiple lacquer layers based either on phosphate or silicate are applied to the component, whereby the lacquer layers differ through the particles added. The component coated with the lacquer layers is heated and then cooled, with a phosphate-glass bond or a silicate-glass bond being formed between the originally separate and discrete lacquer layers.
The inventive protective layer may be formed with a layer sequence of at least two different layers, e.g., a lacquer layer based on phosphate or on silicate with added aluminum powder and/or with added hollow beads and a lacquer layer based on phosphate or silicate with added ceramic particles and/or nitrite particles, arranged with the layers in a repeating sequence and in this way to form a so-called multilayer laminate.
Preferred embodiments of the present invention are derived from the following description.